[HN Gopher] Keeping Time at Stonehenge
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       Keeping Time at Stonehenge
        
       Author : benbreen
       Score  : 23 points
       Date   : 2022-03-05 01:38 UTC (21 hours ago)
        
 (HTM) web link (www.cambridge.org)
 (TXT) w3m dump (www.cambridge.org)
        
       | throw0101a wrote:
       | The book _The Light Ages_ by Seb Falk:
       | 
       | > _In The Light Ages, Cambridge science historian Seb Falk takes
       | us on an immersive tour of medieval science through the story of
       | one fourteenth-century monk, John of Westwyk. From multiplying
       | Roman numerals to navigating by the stars, curing disease, and
       | telling time with an ancient astrolabe, we learn emerging science
       | alongside Westwyk, while following the gripping story of the
       | struggles and successes of an ordinary man in a precarious world.
       | An enlightening history that argues that these times weren't so
       | dark after all, The Light Ages shows how medieval ideas continue
       | to color how we see the world today._
       | 
       | * https://www.goodreads.com/en/book/show/50489364-the-light-ag...
       | 
       | * https://wwnorton.com/books/9781324002932
       | 
       | Has a chapter or two of keeping the calendar:
       | 
       | * https://en.wikipedia.org/wiki/Liturgical_year
       | 
       | and actual time for daily services:
       | 
       | * https://en.wikipedia.org/wiki/Liturgy_of_the_Hours
       | 
       | It should also be noted that for time periods measured over
       | millennia, one may also keep in mind that there are subtle
       | changes in the night sky because of the wobbling of the Earth on
       | its axis of spin:
       | 
       | * https://en.wikipedia.org/wiki/Axial_precession
       | 
       | So that (e.g.) the North Star that we have today (Polaris) is not
       | what not the same as in the past, and will change in the future:
       | 
       | * https://en.wikipedia.org/wiki/Pole_star
       | 
       | The Hoover Dam in the US actually makes use of this astronomical
       | fact in a monument to indicate to possible future generations
       | when it was built:
       | 
       | > _But that point near Polaris, which we call the North Star, is
       | actually slowly moving and tracing a circle through the night
       | sky. While Polaris is our North Star, Hansen's terrazzo floor
       | points out that the North Star of the ancient Egyptians, as they
       | built the great pyramids, was Thuban. And in about 12,000 years,
       | our North Star will be Vega. The workings of this precession are
       | best explained with an animation, as in figure 1. Here you can
       | see how the axis of the earth traces a circle in the sky over the
       | course of 25,772 years._
       | 
       | * https://medium.com/the-long-now-foundation/the-26-000-year-a...
        
       | fennecfoxen wrote:
       | adjusting Stonehenge for daylight savings time has got to be the
       | worst job ever.
        
         | messe wrote:
         | I wonder how they managed leap seconds. Maybe the soil there is
         | particularly malleable, and that's why they chose that
         | location.
        
           | kingcharles wrote:
           | And don't even ask about the year zero bug. If you wonder why
           | they abandoned Stonehenge... well, now you know.
        
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       (page generated 2022-03-05 23:01 UTC)